Predictors for Transfusion Requirement in Haemoglobin E-β Thalassemia

HaemoglobinE-beta thalassemia is a common haemolytic anaemia in Southeast Asia.1 HbE (β-26 glutamine→lysine) is the commonest haemoglobin variant in India with prevalence of 7-50% in North Eastern region and 2.78% in West Bengal.2,3 The clinical picture shows a wide range of heterogeneity produced by the interaction of various factors. Thus, it ranges from mild asymptomatic anaemia to symptomatic manifestations which include refractory anaemia, splenomegaly and sometimes unexplained jaundice.4 The frequency of blood transfusion (BT) requirement varies greatly among patients; but no specific marker to predict the BT frequency is available. Several genetic modifiers affect the phenotype, including the type of β-thalassemia mutation, HbF levels, and co-inheritance of α-Thalassemia. The reasons for the extraordinary clinical heterogeneity of HbE/β-thalassemia are not completely understood.5 The condition may present as a mild and asymptomatic anaemia, or as a life-threatening disorder requiring transfusions from infancy.6 Attempts to categorize the severity of Hb E/β-thalassemia have included the assignment of patients to “severe” and “mild” disease groups, between which putative genetic and environmental factors were then compared.7, 8 Sripichai O et al worked on a scoring system for the classification of beta-thalassemia/HbE disease severity based on six independent parameters; haemoglobin level, age at disease presentation, age at first blood transfusion, requirement for transfusion, spleen size and growth and development.9 They were able to separate patients into three distinctive severity categories: mild, moderate, and severe courses. The present study aims to find out factors that can predict the frequency of BT required by such patients.